Informatics Publishing Limited

P. D. Kamala Jayanthi ¹, G. S. Prakash ²

Affiliations
1 Division of Entomology and Nematology, Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore 560089, IN
2 Division of Fruit Crops, IIHR, Bangalore, IN

Abstract

Pruning is a regular practice followed in grapevine, Vitis vinefera L., to keep the vine manageable and productive. However, immediately after pruning, the plants put out a new flush of leaves which attract several leaf-feeding insects, leading to defoliation and crinkling. Incidence of tip withering bug, Anoplocnemis phasiana (Fab.), usually coinciding with the period of halting practice, results in die-back of shoot tip and prevents extension of the shoot, thus halting shoot growth. Intricacies involved in incidence of this coreid bug on grapevine are discussed here.

Keywords

Tip Withering Bug, Anoplocnemis phasiana, Grape.

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J. Satisha ¹, G. S. Prakash ², R. M. Bhatt ³, P. Sampathkumar ²

Affiliations
1 National Research Centre for Grapes, P.B. # 3, Manjari Farm, Solapur Road Pune – 412 307, IN
2 Division of Fruit Crops, Indian Institute of Horticultural Research, Bangalore - 560 089, IN
3 Division of Plant Physiology and Biochemistry, Indian Institute of Horticultural Research, Bangalore - 560 089, IN

Abstract

Four varieties of grape namely Flame Seedless, Thompson Seedless, Sharad Seedless and Tas-A-Ganesh were subjected to different levels of moisture stress to study their physiological response. Stress was imposed for 14 days by withholding irrigation. Observations on relative water content, leaf water potential, leaf osmotic potential and gas exchange parameters like photosynthetic rate, transpiration rate, stomatal conductance and water use efficiency (WUE) were recorded. None of the varieties could survive for 14 days without irrigation (100% stress). Flame Seedless and Thompson Seedless at 50% moisture stress maintained higher turgidity as indicated by lesser reduction in relative water content and water potential attributed to better osmotic adjustment. Marginal reduction in photosynthesis and greater reduction in transpiration rate in the variety Flame Seedless may have resulted in higher WUE under moisture stress. Higher photosynthetic rate, lower transpiration rate, higher water relation parameters and high WUE in Flame Seedless under soil moisture stress indicated its better tolerance to drought.

Keywords

Grape Varieties, Soil Moisture Stress, Water Potential, Water Use Efficiency.

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J. Satisha ¹, G. S. Prakash ², G. S. R. Murti ³, K. K. Upreti ³

Affiliations
1 National Research Centre for Grapes, P.B. # 3, Manjari Farm, Solapur Road, Pune-412 307, IN
2 Division of Fruit Crops, Indian Institute of Horticultural Research, Bangalore-560 089, IN
3 Division of Plant Physiology and Biochemistry, Indian Institute of Horticultural Research, Bangalore-560 089, IN

Abstract

Studies on ischolar_main and shoot morphology, endogenous hormones and water use efficiency in five grape ischolar_mainstocks namely Dogridge, 1613 C, Salt Creek, St. George and Vitis champinii clone (VC Clone) at three levels of moisture stress viz., no stress (100% irrigation), 50% stress (50% irrigation) and 100% stress (without irrigation) for 14 days revealed that Dogridge and Salt Creek ischolar_mainstocks maintained the highest ratios of ischolar_main to shoot length and ischolar_main to shoot dry weight as compared to other ischolar_mainstocks. Water use efficiency increased with increased soil moisture stress and was the highest in Dogridge and Salt Creek. The abscisic acid content in the leaves of Dogridge was maximum at 50% stress followed by that of Salt Creek. Similarly the cytokinin content (both t-ZR and DHZR) was minimum in Dogridge and Salt Creek at 50% stress while it was maximum in 1613 C and St.George. The ischolar_main to shoot length ratio was positively correlated with ABA content under moisture stress conditions. The higher levels of abscisic acid content in Dogridge and Salt Creek under soil moisture stress suggested their better drought tolerance capacity through a reduction of stomatal conductance and increased water use efficiency.

Keywords

ABA, Cytokinins, Grape Rootstocks, Root to Shoot Length Ratio, Root to Shoot Dry Weight Ratio, Water Use Efficiency.

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